1 files changed, 20 insertions, 2 deletions
diff --git a/base/android/trace_event_binding.cc b/base/android/trace_event_binding.cc
index f802f3d..e261411 100644
--- a/base/android/trace_event_binding.cc
+++ b/base/android/trace_event_binding.cc
@@ -9,6 +9,7 @@
 #include <set>
 
 #include "base/debug/trace_event.h"
+#include "base/debug/trace_event_impl.h"
 #include "base/lazy_instance.h"
 #include "jni/TraceEvent_jni.h"
 
@@ -54,10 +55,27 @@ class TraceEventDataConverter {
   DISALLOW_COPY_AND_ASSIGN(TraceEventDataConverter);
 };
 
+class TraceEnabledObserver : public debug::TraceLog::EnabledStateObserver {
+  public:
+    virtual void OnTraceLogEnabled() OVERRIDE {
+      JNIEnv* env = base::android::AttachCurrentThread();
+      base::android::Java_TraceEvent_setEnabled(env, true);
+    }
+    virtual void OnTraceLogDisabled() OVERRIDE {
+      JNIEnv* env = base::android::AttachCurrentThread();
+      base::android::Java_TraceEvent_setEnabled(env, false);
+    }
+};
+
+base::LazyInstance<TraceEnabledObserver>::Leaky g_trace_enabled_state_observer_;
+
 }  // namespace
 
-static jboolean TraceEnabled(JNIEnv* env, jclass clazz) {
-  return base::debug::TraceLog::GetInstance()->IsEnabled();
+static void RegisterEnabledObserver(JNIEnv* env, jclass clazz) {
+  bool enabled = debug::TraceLog::GetInstance()->IsEnabled();
+  base::android::Java_TraceEvent_setEnabled(env, enabled);
+  debug::TraceLog::GetInstance()->AddEnabledStateObserver(
+      g_trace_enabled_state_observer_.Pointer());
 }
 
 static void StartATrace(JNIEnv* env, jclass clazz) {